Wireless communication systems are widely deployed to provide various types of communications such as voice, data, video and so on. These systems may be multiple-access systems capable of supporting communication with multiple access terminals by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems or hybrids involving at least two of these systems. Typically, a wireless communication system comprises several base stations, wherein each base station communicates with the mobile station using a forward link and each mobile station (or access terminal) communicates with base station using a reverse link.
With the advent of these wireless communication systems that facilitate varied communications, bandwidth demands as well as user volume has increased. Accordingly, information is transmitted at different rates depending on particular requirements which can vary from user to user. Furthermore, volume of users, multipath etc. are all causes for severe interference within communication systems. Therefore, managing interference within a communication system, e.g., a wireless communication system, is an important task in order to ensure link robustness and to achieve high system capacity. In particular, for cellular communication systems, a number of interference cancellation algorithms are currently in use, but they are generally implemented at a base station receiver. Therefore, they can be employed only in reverse link communications from a mobile terminal to a base station wherein the base station has the ability to process communications from different users simultaneously.
When investigating methods to reduce interference on forward links from the base station to mobile terminals, various factors need to be considered. This is because the environment of a mobile terminal can change constantly. As the terminal moves from place to place it encounters signals of varying strengths from different sources. Hence, no single static formula is effective to counter the interference from such varied sources as received by the mobile terminal. Moreover, it is likely that the mobile terminal will experience interference from a source that was never encountered earlier. As a result, it is difficult to plan ahead for mitigating interference effects at receivers within mobile terminals.